…Key_blocks_unused’, ’28987′ ‘Key_blocks_used’, ’1332′ ‘Key_read_requests’, ’1552507′ ‘Key_reads’, ’1654′ ‘Key_write_requests’, ’114303′ ‘Key_writes‘, ’1346′ ‘Max_used_connections’, ’651′ ‘Not_flushed_delayed…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
…Key_reads | 198208 | | Key_write_requests | 469220 | | Key_writes | 185808 | +————————+———+ 7 rows in set (0.00 sec) So how long does it take: mysql…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…maintaining materialized views. While writing Flexviews, I learned how… but right now only MySQL storage nodes are supported…. merge optimization enabled: ON DUPLICATE KEY UPDATE `origin_airport_id`=… flight_delayed`=`sum(DepDelay >= 0) flight_delayed` + VALUES(`sum(DepDelay >= 0) flight_delayed`) –…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… their own clients, with no delays. Finally, the analysis is usually multi… initial insertion, because you can write CSV files with any programming language….are already inconvenient limitations on some key parts of partitioning, such as … using MySQL 5.1′s row-based replication, or in MySQL 5.0…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…`), KEY `DepDelay` (`DepDelay`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT=’Contains all avaialble data from 1988 to 2010′; mysql> use ontime1; Database changed mysql… my.cnf [client] port=3306 socket=/tmp/mysql-inno.sock [mysqld] socket=/tmp/mysql-inno.sock default-storage-engine=INNODB innodb-buffer… innodb-thread-sleep-delay=0 innodb-use-sys-stats-table innodb-write-io-threads=4 join-buffer-size=16M key-buffer-size=64M…
Post: Performance gotcha of MySQL memory tables
February 1, 2008 By 5 Comments
… know about comes from the fact it is the only MySQL storage engine which defaults to HASH index type by default…. This is however not performance gotcha I’m going to write about. There is one more thing you should be aware… could delay writes and do all the changes directly in memory. MyISAM however had to perform number of random writes to the key file…
Post: Percona XtraDB Cluster (PXC): what about GRA_*.log files ?
December 19, 2012 By Leave a Comment
…_3.log: data [root@node2 mysql]# ls -l GRA_3_3.log -rw-rw—-. 1 mysql mysql 106 Nov 29 23:28 GRA…-bin.log: MySQL replication log [root@node2 mysql]# mysqlbinlog -vvv GRA_3_3-bin.log /*!40019 SET @@session.max_insert_delayed_threads=0… Write_rows event on table sakila.actor; Duplicate entry ’447′ for key ‘PRIMARY’, Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY…
Post: Percona Toolkit 2.1 with New Online Schema Change Tool
April 5, 2012 By 10 Comments
…. Client applications can continue reading and writing the table with no interruption. With… anyone experiences with MySQL is significantly alleviated. If you’ve ever delayed a project…key is that it is replication-aware and inspects replicas, throttles its operation to avoid causing replication delay…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… about last failed foreign key constraint: ———————— LATEST FOREIGN KEY ERROR ———————— 060717 4:29…_thread_sleep_delay variable. Value is specified in microseconds. mysql tables in use… writes are done to OS cache, and being sequential writes these logs writes are pretty…
Post: Why you don't want to shard.
August 6, 2009 By 34 Comments
… a RAID 10 controller w/battery backed write cache, the slave delay problem is actually very hard to … busy tables, and move them onto their own MySQL server. Partition-by-function keeps the architecture… into the above constraints. Sharding by hash or key – This method works by picking a column on…
